Workshop 4-1: Radiation Boundaries - UPRMrafaelr/inel6068/HFSS/HFSS_Antenna_v2015_v1/... ·...

Release 2015.0 May 6, 2015 1 © 2015 ANSYS, Inc.

2015.0 Release

Workshop 4-1: Radiation Boundaries

ANSYS HFSS for Antenna Design


Example: Radiation Boundaries

• Planer Inverted-F Antenna • This example is intended to show you how to apply a Radiation Boundary and how it’s size can impact the solution.

• Overview • Antenna simulated using an ABC (Absorbing Boundary Condition)

– Parametric Analysis

• Antenna simulated using an PML (Perfectly Match Layer)

– Three Simulations l/20, l/10 and l/4

• Antenna Simulated using FE-BI

– Parametric Analysis


Getting Started

• Launching ANSYS Electronics Desktop 2015 • To access ANSYS Electronics Desktop, click the Microsoft Start button,

– Select Programs > ANSYS Electromagnetics > ANSYS Electromagnetics Suite 16.0. Select ANSYS Electronics Desktop 2015

• Setting Tool Options • Note: In order to follow the steps outlined in this example, verify that the following tool options are set:

• Select the menu item Tools > Options > HFSS Options...

– Click the General tab

• Use Wizards for data input when creating new boundaries: Checked

• Duplicate boundaries/mesh operations with geometry: Checked

– Click the OK button

• Select the menu item Tools > Options > 3D Modeler Options….

– Click the Operation tab

• Select last command on object select: Checked

– Click the Display tab

• Set default transparency to 0.7

– Click the Drawing tab

• Edit properties of new primitives: Checked



Open Project

• Opening a Project • In the ANSYS Electronics Desktop, select the menu item File > Open

– Browse to the folder containing the file PIFA_Training.aedt and select Open

– Select the menu item File > Save As.

• From the Save As window, type the Filename: PIFA_W_ABC.aedt


Radiation Boundary

• Applying Radiation Boundary • Select the menu item Edit > Select > Objects

• Select the menu item Edit > Select > By Name...

– Select AirBox and click OK

• Select the menu item Edit > Select > All Object Faces

• Select the menu item HFSS > Boundaries > Assign > Radiation...



Radiation Boundary

• Applying Mesh Operation on Radiation Boundary • Select the menu item Edit > Select > Objects




• Select the menu item HFSS > Mesh Operations > Assign > On Selection > Length Based

– Maximum Length of Elements: 2cm

• Click the OK button

Note: To improve far field results for any distance, the radiation boundary needs to be seeded with lambda/6 mesh operation at the highest frequency. Solution frequency is 2.5GHz, lambda = 12cm, lambda/6 = 2cm Therefore we set the mesh operation to 2cm


Radiation Boundary

• Create a Radiation Setup • Select the menu item HFSS > Radiation > Insert Far Field Setup > Infinite Sphere...

– In the Infinite Sphere Tab

– Name: Infinite Sphere 1

• Phi:

– Start: 0 deg

– Stop: 90 deg

– Step Size: 90 deg

• Theta:

– Start: 0 deg

– Stop: 180 deg



• Model Validation • Select the menu item HFSS > Validation Check

• Click the Close button


Parametric Sweep

• Creating a Parametric Sweep • Select the menu item HFSS > Optimetrics Analysis > Add Parametric...

– In the Sweep Definitions tab.

• Click the Add... button

– Variable: AirBox_dist

– Select the radio button: Linear step

– Start: 0.5 cm

– Stop: 5 cm

– Step: 0.5 cm

– Click the Add>> button


– Click the Options tab.

• Save Fields and Mesh: Checked


• Save Project • Select the menu item File > Save

• Analyze the Project • Select the menu item HFSS > Analyze All

Note: Saving Fields and Mesh will save all the field data for all Discrete and Last Adaptive solutions. To reduce the disk space requirements we can choose to save only the far field data, and not the field data inside of the entire volume.


Smith Chart

• Create Smith Chart

• Select the menu item HFSS > Results > Create Terminal Solution Data Report > Smith Chart

– Solution: Setup1: Sweep

– In the Trace tab:

• Category: Terminal S Parameter

• Quantity: St(1,1)

• Function: <none>

– Click the New Report button

– Click the Close button

Note: The S-parameter stabilizes at lambda/4, from the radiating element. We recommended that you size the air volume lambda/4 at the lowest frequency. This example has a lower sweep point of 2 GHz and a lambda/4 of 4cm.


Rectangular Plot

• Create Rectangular Plot

• Select the menu item HFSS > Results > Create Terminal Solution Data Report > Rectangular Plot


– Domain: Sweep




• Function: dB



• Trace characteristics

• Right-click in XY Plot1 (in Report window)

• Select Trace Characteristics > All...

– Scroll-down to the bottom and select XatYMin

• Click the Add Trace Charateristic button


Note: The resonant frequency stabilizes at 2.55 GHz when the radiation boundary is greater then 4 cm away from the antenna. This is the distance where the boundary condition is not loading the antenna but absorbing the radiated energy


Far Field Plot

• Create Far Field Radiation Pattern • Select the menu item HFSS > Results > Create Far Fields Report > Rectangular Plot

– Solution: Setup1: LastAdaptive

– Geometry: Inifinite Sphere1


• Category: Realized Gain

• Quantity: RealizedGainTotal

• Function: dB

– Click the Families Tab

• Click the Edit button

associated with Phi variable

– Click 0deg in the pop-up window

– Close the pop-up window by

clicking the X button

• Freq: 2.5 GHz

• Airbox_dist: All



Note: The peak gain value converges toward .5 dB as the air volume increases beyond l/4


Antenna with PML

• Antenna simulated using an PML (Perfectly Match Layer)

– Three Simulations l/20, l/10 and l/4

• This example will demonstrate the use of the PML boundary condition

• Compare Return Loss for different distances to the PML

• Compare Radiation Patterns for different distances to the PML


PML Setup Wizard

• PML Setup Wizard • Helps create objects with appropriate material properties

• PML Inputs • Uniform Layer Thickness

– Thickness of PML Object Created (recommended > λ/3)

• Minimum Frequency

– Minimum frequency that PML will be absorbing

• Minimum Radiating Distance

– Distance from radiating object to PML Object (recommended > λ/8)

1

2

PML Object Minimum Radiating Distance

Uniform Layer

Thickness

Air Box

PML Corner

Object Radiating Element


Creating PML

• Opening a Project – From the Electronics Desktop, click the On the Standard toolbar, or

select the menu item File > Open

– Select the project PIFA_W_PML.aedt

– Select Design “1_PIFA Lambda_by_20”

• Applying PML Boundary • Select the menu item Edit > Select > Objects




• Select the menu item HFSS > Boundaries > PML Setup Wizard...

– Select Create PML Cover objects on Selected Faces radio button

• Uniform Layer Thickness: 5 cm

– Click the Next button

– Select PML Objects Accept Free Radiation radio button

• Min Frequency: 2 GHz

– Minimum Radiating Distance: 0.75 cm

– Click the Next button

– Click the Finish button

The PML wizard will create a uniform layer thickness, use λ/3 of lowest frequency λ=15cm @ 2GHz, therefore use a value of 5cm Distance from radiating object to PML Object (λ/20) = 0.75cm


Mesh Operation





• Select the menu item HFSS > Mesh Operations> Assign > On Selection> Length Based...



Note: To improve far field results for any distance, the radiation boundary needs to be seeded with lambda/6 mesh operation at the highest frequency. Solution frequency is 2.5GHz, lambda = 12cm, lambda/6 = 2cm Therefore we set the mesh operation to 2cm


Radiation Boundary



– Name: Infinite Sphere1

• Phi:

– Start: 0 deg

– Stop: 90 deg


• Theta:

– Start: 0 deg

– Stop: 180 deg




Rectangular Plot




– Domain: Sweep




• Function: dB




Far Field Plot







• Function: dB







• Freq: 2.5 GHz




Simulation Setup

• Simulation Setup • Select the Design “2_PIFA Lambda_by_10”

• Repeat the steps from slide 14 to 18

– Except Minimum Radiating Distance for PML Setup: 1.5cm

• Select the Design “3_PIFA Lambda_by_4”

• Repeat the steps from slide 14 to 18

– Except Minimum Radiating Distance for PML Setup: 3.75cm


• Analyze Project • From the Project Manager window, Right-click on the project PIFA_W_PML

– Select Analyze All

Note: This will solve all of the designs in this project.


Comparing Return Loss Results

• Comparing Return Loss • Select the Design “2_PIFA Lambda_by_10”

• Expand Results, right-click on dB(St(1,1)) under XY Plot 1

– Select Copy Data

• Select the Design “1_PIFA Lambda_by_20”

• Expand Results, right-click on XY Plot1

– Select Paste

– Click on dB(St(1,1)), and from the Properties window

• Check the box for Specify Name

• Name: dB(St(1,1))_Lambda_by_20

– Click on dB(St(1,1))_1, and from the Properties window

• Name: dB(St(1,1))_Lambda_by_10

• Similarly, copy the Return Loss dB(St(1,1) from “3_PIFA Lambda_by_4” and paste into design “1_PIFA Lambda_by_20”

– Rename it to dB(St(1,1))_Lambda_by_4


Comparing Return Loss Results


• Double-click on XY Plot 1 in the design 1_PIFA Lambda_by_20

• Select the menu item Report2D > Trace Characteristics > All...

• Select Scroll-down to the bottom and select XatYMin



Note: The results of all three are almost identical. We recommended that you use a PML with a λ/10 minimum spacing from the radiating element


Comparing Radiation Pattern

• Comparing Radiation Pattern plots

• Repeat the same procedure as shown in Slide 20 for comparing Radiation pattern between the three designs for XY Plot 2

• Double-click on XY Plot 2 in the design 1_PIFA Lambda_by_20


• Select the menu item Report2D > Trace Characteristics > All...

• Select Scroll-down to the bottom and select YatXVal

– X Value: 90deg

– Click the Add Trace Charateristic button



FEBI

• Opening a Project • In the ANSYS Electronics Desktop, select the menu item File > Open

– Browse to the folder containing the file PIFA_Training.aedt and select Open

– Select the menu item File > Save As.

• From the Save As window, type the Filename: PIFA_W_FEBI.aedt


Radiation Boundary

• Applying Radiation Boundary • Select the menu item Edit > Select > Objects




• Select the menu item HFSS > Boundaries > Assign > Radiation...

• Model exterior as HFSS-IE domain: Checked



Radiation Boundary





• Select the menu item HFSS > Mesh Operations > Assign > On Selection > Length Based




Radiation Boundary



– Name: Infinite Sphere 1

• Phi:

– Start: 0 deg

– Stop: 90 deg


• Theta:

– Start: 0 deg

– Stop: 180 deg



• Model Validation • Select the menu item HFSS > Validation Check



Parametric Sweep

• Creating a Parametric Sweep • Select the menu item HFSS > Optimetrics Analysis > Add Parametric...

– In the Sweep Definitions tab.

• Click the Add... button

– Variable: AirBox_dist

– Select the radio button: Linear step

– Start: 0.5 cm

– Stop: 5 cm

– Step: 0.5 cm

– Click the Add>> button


– Click the Options tab.

• Save Fields and Mesh: Checked



• Analyze the Project • Select the menu item HFSS > Analyze All


Smith Chart

• Create Smith Chart

• Select the menu item HFSS > Results > Create Terminal Solution Data Report > Smith Chart





• Function: <none>



Note: With FE-BI enabled on the radiation boundary the air box volume does not effect the return loss measurement an appreciable amount


Rectangular Plot




– Domain: Sweep




• Function: dB




• Right-click in XY Plot1 (in Report window)

• Select Trace Characteristics > All...

– Scroll-down to the bottom and select XatYMin



Note: The variation in the resonant frequency is +/- .2%, FE-BI gives accuracy at any air volume size


Far Field Plot







• Function: dB







• Freq: 2.5 GHz

• Airbox_dist: All



Note: The variation in the gain is 0.1dB, FE-BI gives accuracy at any air volume size

Workshop 4-1: Radiation Boundaries - UPRMrafaelr/inel6068/HFSS/HFSS_Antenna_v2015_v1/... ·...

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